Multiple depressive episodes and plasma postdexamethasone cortisol levels.

The hypothalamic-pituitary-adrenal (HPA) axis is dysregulated in many patients with major depressive disorder (MDD). To determine whether or not a past history of depressive episodes is associated with this dysregulation, we studied the relationships among number of past depressive episodes, number of previous hospitalizations for depression, and number of years since first depressive episode and biological markers of depression (postdexamethasone plasma cortisol levels and dexamethasone suppressor/nonsuppressor status). No significant relationships were detected.